When Windows 10 officially launches on July 29, it will ship with a new default Web browser called Edge. For Web developers who struggled with maintaining compatibility with Internet Explorer, the change spells good news, according to Frank Olivier, principal program manager lead for Microsoft Edge.
But first, Microsoft is appealing to developers to exercise caution when detecting a browser's user agent (UA) string.
"We recommend that Web developers avoid UA-sniffing as much as possible; modern Web platform features are nearly all detectable in easy ways," wrote Olivier in a lengthy blog post preparing the developer community for the browser's arrival. "Over the past year, we've seen some UA-sniffing sites that have been updated to detect Microsoft Edge … only to provide it with a legacy IE11 [Internet Explorer 11] code path," he continued.
It's a tactic that can unravel some of the work Microsoft has done to implement today's Web standards, warned Olivier.
"This is not the best approach, as Microsoft Edge matches 'WebKit' behaviors, not IE11 behaviors (any Edge-WebKit differences are bugs that we're interested in fixing)," he said. WebKit is an open-source layout engine for Web content used by Apple's Safari browser. Google Chrome is based on a fork of the software called Blink. "In our experience, Microsoft Edge runs best on the 'WebKit' code paths in these sites."
Olivier also reiterated Microsoft's willingness to drop some of its own Web technologies for a better user and developer experience.
"To further ensure that Websites don't detect our new engine as Internet Explorer, we also spent a lot of time removing legacy IE-isms (No more ActiveX!)," he noted. And those efforts are paying off, he claimed.
"During development, Microsoft Edge has consistently been more interoperable with the broader Web than any previous Microsoft browser," Olivier said. "We've endeavored to align with other browsers where it is the best thing for the Web, and we've worked with other vendors and the standards bodies to fix issues on their side."
To further appeal to Web developers, Microsoft said yesterday that it had open-sourced its Test Drive demos.
"As we rapidly approach the July 29 release of Windows 10 and Microsoft Edge, we wanted to get in the spirit of 'a break from the past' by launching a new Test Drive as part of the new Microsoft Edge Developer Site," Antón Molleda, Microsoft Edge program manager, said in a statement.
The updated resource site provides "Web developers with feature demos that demonstrate how to build interoperable code based on new Web platform features," said Molleda. New demos include new animated CSS3 filters, a Web audio tuner and PhotoCapture picture-taking test code.
"To make this process as easy as possible, we are excited to open-source all our feature demos on GitHub, so anyone can learn and reuse this code in any Website (or contribute fixes!)," said Molleda.